[runtime] Allocate space for computed property names

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index bf51b3640b04e31d3af7e7d452cc1034f93bf6ac..2f53c0eed9738de0bfdad4edb914876f92c7c69e 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -195,6 +195,8 @@ bool HeapObject::IsFixedArray() const {
          instance_type == TRANSITION_ARRAY_TYPE;
 }
 
+bool HeapObject::IsConstantProperties() const { return IsFixedArray(); }
+
 // External objects are not extensible, so the map check is enough.
 bool HeapObject::IsExternal() const {
   return map() == GetHeap()->external_map();
@@ -619,6 +621,7 @@ CAST_ACCESSOR(Code)
 CAST_ACCESSOR(CodeCacheHashTable)
 CAST_ACCESSOR(CompilationCacheTable)
 CAST_ACCESSOR(ConsString)
+CAST_ACCESSOR(ConstantProperties)
 CAST_ACCESSOR(DeoptimizationInputData)
 CAST_ACCESSOR(DeoptimizationOutputData)
 CAST_ACCESSOR(DependentCode)